Nociceptin/orphanin FQ suppresses adaptive immune responses in vivo and at picomolar levels in vitro.

Nociceptin/orphanin FQ (N/OFQ), added in vitro to murine spleen cells in the picomolar range, suppressed antibody formation to sheep red blood cells in a primary and a secondary plaque-forming cell assay. The activity of the peptide was maximal at 10(-12) M, with an asymmetric U-shaped dose-response curve that extended activity to 10(-14) M. Suppression was not blocked by pretreatment with naloxone.

Vaccines against morphine/heroin and its use as effective medication for preventing relapse to opiate addictive behaviors.

Current pharmacotherapies for treating morphine/heroin dependence are designed to substitute or block addiction by targeting the drug itself rather than the brain. The heroin addict is still being exposed to addictive opiates, and consequently may develop tolerance to and experience withdrawal and drug's toxic effects from the treatment with high incidence of relapse to addictive drug consumption. As for other drugs of abuse, an alternative approach for morphine/heroin addiction is an antibody-based antagonism of heroin's brain entry.

Endomorphin 1 and endomorphin 2 suppress in vitro antibody formation at ultra-low concentrations: anti-peptide antibodies but not opioid antagonists block the activity.

Endomorphin 1 (EM-1) and endomorphin 2 (EM-2) were tested for their capacity to alter immune function. Addition of either of these peptides to murine spleen cells in vitro inhibited antibody formation to sheep red blood cells in a bi-phasic dose dependent manner. Maximal inhibition was achieved at doses in the range of 10(-13) to 10(-15)M.